X-ray tube.



H. GREEN.

X-RAY TUBE.

APPLICATION FILED J'ULY'IZ, 1912.

1,042,109, Patented 0011.22, 1912.

WITNESSES f IINVENTOR Henry Green ATTORNEY UNITED sTA'rns PATENT cru se,

HENRY GREEN,1OF HARTFORD, CONNECTIGUTp X-RAY' TUBE.

Application filed July 12,1912. Seria11o.'709.,058.

To all whom it may concern:

Be it known that I, HENRY GREEN, a citizen of the United States,residing at Hart ford, county of Hartford, and State of Connecticut,have invented certain new'and use-. ful Improvements 1n X-Ray Tubes, ofwhich the following is a specification.

'The object'of this invention is to produce a device. of theoharacter'described having features of novelty and advantage.

Fi re 1 of the drawings shows a tube embodying my invention. Fig. 2shows a modification.

'Referring to the drawings, a denotes an- X-ray tube of'usual formhaving the central bulbous portion 00 and the oppositely arrangedtubular extensions b-c to receive the usual anode (Z and cathode e.

f denotes a conventional form of regulator by means of which the vacuumof the tube may be reduced when desired.

As thus far described the tube is of usual and well known construction.

My invention resides inproviding an additional electrode 10 of tubularform the inner end of which is located in operative relation with theanode and preferably at a short distance therefrom and at the rearthereof, this electrode extending intoan extension .11 for a substantialdistanc'e. A wire of conducting material 12 attached to the outer end ofthis electrode is sealed through the end of the extension 11 to providean exterior terminal which is illustrated as connected with the anodeterminal by. the conducting wire 14, though in some cases it may bedesirable to omit this connection.

In the form in which I have practised this invention a considerableportion of the length of the electrode 10 is confined within the tubularextension 11. As a result of this construction a tube, having a vacuumwhich is relatively low in comparison with tubes as now made, gives apenetration of the higher vacuum tubes of the old type and the cleardefinition of the lower vacuum tubes, enabling the operator to makerapid pictures .of soft tissuesand bone structures on the same plate, atconsiderable depth,

' withclear definition and at a short exposure;

Specification of Letters mat.

Patented Oct. 22,1912. I

quired for the cathode stream is interposed between the cathode andanode, and when using heavy currents this gas interferes withthe'=passing of the cathode stream, blunting the focus to some extentand reducing the penetration.

In the operation of a tubemade in accordance with my invention,particularly during the pumping stage, a phenomena ap pears whichindicates that the excess of 'gas in the tube over that required for thepassage of the cathode stream is drawn up into this tubular electrodeand there held, removing it from the path of the cathode stream. I amaware that this third elecindicated in Fig. 1, might be formed by aclosely coiled wire as illustrated at 15 in Fig. 2 and possibly in otherways. But the essential feature is that it shall be of tubular formwhether its cross section be round, square or anything between, and ofsufficient length that its inner end shall be in operative relation withthe anode and its outer end projected into an extension from the glassbulb.

I claim as my invention:

. 1.,The combination with an X-ray tube including the usual cathode andanode elec *trode instead of having a solid wall, as

trodes, of a third electrode oftubular form located within the tube withone end in relative operative proximity to said anode.

2. The combination with an X-ray tube trodes, of a third electrode oftubular form supported within thetube with one end arranged in operativerelation with the anode, the other end projecting into a tubularextension of the tube.

' including the usual cathode and anode elec- 3.'The combination with anX-ray tube said third electrode being. electrically conincluding theusual cathode and anode ele cnected with the terminal exterior of thetrodes, of a tubular extension from the wall tube. v of said X-ray tube,and a'third electrode HENRY GREEN. 5 of tubular form having one endlocated Witnesses: 1 within said tubular extension and its other I E.ONEILL,

end in operative relation with said anode, M. A. -SHUoKERow.

